The present invention relates to optical scanning systems and more particularly to an optical bar code scanning system which can be mounted within a checkout counter or other type of support member for scanning bar code labels on a merchandise item which is moved past a scanning aperture located in the bar code scanner.
In present-day merchandising point-of-sale operations, data pertaining to the purchase of a merchandise item is obtained by reading data encoded indicia such as a bar code printed on the merchandise item. In order to standardize the bar codes used in various point-of-sale checkout systems, the grocery industry has adapted a uniform product code (UPC) which is in the form of a bar code. Various reading systems have been constructed to read this type of bar code, including hand-held scanners which are moved across the bar code and stationary optical reader systems normally located within the checkout counter in which the bar code is read by projecting a plurality of scanning light beams through a window constituting the scanning area of the counter over which a bar code printed on a purchased merchandise item or on a bar code label attached to the merchandise item is moved. This scanning operation is part of the process of loading the item into a baggage cart. In scanning the bar code label, a scan pattern is generated by the scanning apparatus which consists of a plurality of individual scanning lines oriented in various directions so as to enable the scan pattern to scan the bar code label irrespective of its orientation with respect to the scan pattern. The most common prior art scan pattern is in the form of an X together with an horizontal line. To generate a scan pattern containing more scan lines would require a more complex mirror arrangement within the scanning apparatus which increases the cost of the scanning apparatus. Scanning systems presently found in checkout counters comprise a large structure mounted within the counter having a number of mirrors mounted so as to occupy the internal area of the checkout counter. It would be desirable to have a compact optical scanner which would be not only low in cost but which would be able to produce a scanning pattern composed of a dense pattern of scan lines and which would not occupy a large portion of the checkout counter.